#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	FILE* pf = fopen("example.txt", "r");
	if (pf == NULL)
	{
		perror(" fopen fail");
		return 1;
	}
	fputs("hello world", pf);
	char arr[] = "##########";
	fgets(arr, 5, pf);
	puts(arr);
	fclose(pf);
	pf = NULL;
	return 0;
}